Lamp holder assembly for luminaire



June 24, 1958 D. w. HARLING LAMP HOLDER ASSEMBLY FOR LUMINAIRE 2 Sheets-Sheet 1 Filed Sept. 28. 1953 INVENTOR.

I BY M ATT/P/VEY June 24, 1958 D. w. HARLING LAMP HOLDER ASSEMBLY FOR LUMINAIRE Filed sept. 28, 195s 2 Sheets-Sheet 2 LAMP HOLDER ASSEMBLY FOR LUMINAIRE Donald` W. Hurling, Milwaukee, Wis., assignor to Mc- Graw-Edison Company, a corporation of Delaware Application September 28, 1953, Serial No. 382,718

Claims. (Cl. 240-25) The present invention relates to luminaires, and particularly relates to a lamp holder assembly for luminaires, such as those used for street lighting purposes.

It has long been the practice in the operation of series connected lamps, such as those that may be used in street lighting installations, to provide a means, such as a film cutout, for maintaining continuity of service in the series circuit when one or more lamps have burned out. Series circuits have been provided in a major share of the installations of both incandescent and gaseous discharge luminaires for the numerous advantages provided by such circuits. One of the disadvantages of operating lamps in series connection has been that it is practically a necessity that the circuit be opened before replacing burnt out lamps, film cutouts, and to perform other maintenance operations because of the relatively high voltage and amperage ordinarily supplied to such circuits, making it unsafe for an operator to work with live parts. Generally, such maintenance work has been performed during the daylight hours, and the maintenance crews must depend upon reports from neighbors or spotter crews to know which lamps have burned out without energizing the entire circuit for the particular purpose of spotting such lamps.

It is among the objects of the present invention to provide a luminaire lamp holder, preferably, but not necessarily in series electrical connection, for receiving either an incandescent lamp, or a gaseous discharge lamp, and having contacts arranged for normal electrical engagement with fixed contacts, which contacts may be disengaged during periodic maintenance operations without disrupting continuity of service in the remaining lamps of the circuit, and with the various parts or the luminaire to 'oe serviced being disconnected from line current.

Another object of the pre-sent invention is to provide a lamp holder for a series-connected luminaire, which includes separable contacts adapted for normal electrical engagement to establish a circuit through a film cutout to the conducting lamp receptacle, and which contacts may be moved towards disengagement without disrupting continuity of service in the series circuit to permit replacement of the cutout and the lamp and other maintenance operations out of danger of physical contact with electrically alive parts.

lt is a specific object of the present invention to provide a lamp holder for a series-connected luminaire including a pair of normally disengaged stationary contact members, each separately normally engaged with a pair of cooperating Contact members -fastened to a lamp socket and having a lm cutout interposed therebetween, wherein said movable contacts may be moved 'towards electrical disengagement with said stationary contacts with said stationary contacts concurrently electrically engaging one another for maintaining electrical continuity in the series circuit.

For a better understanding or the present invention, reference may be had to the accompanying drawings in which;

nited States Patent O ice Fig. 1 is a fragmentary side elevational view, partly in section, of a luminaire, illustrating the various components of the lamp holder in normal operating relationship.

Fig. 2 is a fragmentary view, partly in section, of a portion of a luminaire with the various operating parts rotated to out-of-circuit position.

Fig. 3 is a fragmentary sectional View taken along lines 3-3 of Fig. 2.

Fig. 4 is a fragmentary sectional view taken along lines 4--4 of Fig. 2.

Referring now to Fig. 1 of the drawings, there is illustrated a street lighting luminaire of the enclosed type generally indicated by the reference numeral 1. The particular luminaire illustrated utilizes electrical lamp 2, which may be of the incandescent type c1: the gaseous discharge type, and which has its longitudinal axis disposed in a horizontal plane. it is to be noted, however, that the novel device, described hercinbelow, is equaily applicable to lamps disposed in a vertical operating position, and that the luminaire, itself, is illustrated for descriptive purposes only.

The luminaire, in general, comprises a housing or relector 3, which preferably has a specular surface interiorly thereof for reflecting light rays in a predetermined direction. In an enclosed luminaire of the present type, it is conventional to provide light-transmitting glassware comprising a globe 4, which is of a refractirg` nature. Additional light denectors (not shown) may be provided as desired. The globe may bc ,rr a marginal ange 5 engaging a mounting cushioning resilient gasket 7 interposed t The gasket 7 is preferably of a material that a moisture-proof seal between the rnc bers. conventional to provide a compensating r` arrangement, the hinge portion of which is snow erally by the reference character d. inasmuch as the latch member does not constitute a part or the present invention, it has not been disclosed herein, but may take t any of the usual forms, such as the scribed and claimed in U. S. granted to R. L. Smythe on anuary signed to the same assignee as is the p- In general, the latch member comprises pair of trunnions 9 secured to the housing 3 and provided with hook portions l() for receiving a pivot pin il integral with the globe mounting ring 6. A resilient spring member l2 is mounted on the ring 6, and has its free end cooperating with the trunnions 9 to provide pressure in an upward direction to maintain the moisture-proof seal between the ring and the housing 3. A resilient sealing gasket member 13 is interposed between the housing and the mounting ring peripherally of the globe d to complete the seal.

The preferred mounting arrangement for the lamp holder is to position the lamp receptacle, denoted generally at 20, on a bracket 21 secured to the mounting ring 6 of the globe 4`by means of a machine screw 22 engaging tapped holes in the bracket. it will be apparent from the following description that the receptacie may be mounted in any of various mounting positions without departing from the scope of the present invention, and without interfering with its operating characteristics.

The lamp receptacle 20 comprises a heat and electrical insulating member 23, which is preferably of porcelain, or the like. A conducting socket 'Z4 is mounted interiorly of the insulating member, and may be of the conventional threaded type for receiving either incandescent or gaseous discharge lamps. If it is desired, a conducting member of the bayonet type (not shown) may be provided.

The contact structure comprises a set of stationary contacts and a set of movable contacts, the cooperating members of each set being in normal electrical engagement.

, Y es It is not necessary that the contacts in themselves be movable, but the term is used to denote contact members'thatl may be moved towards separation and electrical disengagement. That is, the terminal connections of the conducting socket are each completed' through the movable contacts and 2d, respectively. As shown inY Fig: 3, the contact is electrically connected to the center contact (not shown) of the lamp base, whereas the generally U-shaped Contact Zo is electrically connected to the threaded lamp receiving portion of the socket 2d; A lilm cutout Sti is interposed between each of the contacts ZS and Zd when the lamp is series-connected, and is arranged to continue the electrical circuit in the conventional manner should the lamp burn out. The cutout 30 is normally non-conducting and becomes conducting after rupture caused by a high surge in the circuit when the lamp E burns out.

As shown in Figs. l and 4, the lamp'holder is positioned in normal operating position with the movable contacts 25 and 2d in eiectrical engagement with the stationary contacts Si and 32, respectively. The stationary contacts are biased towards electrical engagement with one another, as shown in Fig. 2. t is preferable'to provide thel movable contact Z5 of a relatively heavier conducting material than the resilient stationary contactv 3l. This relative material t. kness will permit the movable contact 2S to press the resilient stationary contact 3lV towards disengagement with the stationary contact 32, as is shown in Fig. l. Each of the stationary terminals 3l and 32 are connected to line by means of leads 33 and 34- electrically connected to terminal blocks 35 and 36, respectively.

With the parts in normal operating position, as shown in Fig. l, the circuit may be traced from the leads 33 and 3ftto each of the stationary contacts 3i and 32, respectivel". inasmuch as the globe 4 is in latching relationship with tire housing 3, an upward pressure exerted by the latch member (not shown) and the spring l2 will cause the movable contact 25 to become electrically engaged with the stationary contact 3i, and further to press that contact upwardly and out of electrical engagement with the stationary contact 32. The circuit may then be completed from the contact 3l to the Contact 25 connected to the lamp, and then through the conducting portions of the lamp. Current may then travel from the lamp to the socket 2d and to the movable terminal 26 fastened thereto. established through the stationary Contact 32 the terminal block 36, to the lead 3d, thereby connecting the luminaire in series relationship with the remainder of the lamps on the circuit.

Y Should it be necessary to replace a burnt out lamp or to perform other maintenance operations such as clean-- ing of the globe, etc., the various movable parts may be rotated to the position shown in Fig. 2. lt will be apparent that as the parts are moved to the position shown in Fig. 2, the upward force on the stationary contact 3l will be removed, and that contact will become electrically engaged with the stationary contact 32 to provide a shunting means for maintaining the electrical circuit throughout the series-connected system. It is to be noted, that if a lamp had previously burned out, the circuit would have been short-circuited through the lm cutout 3@ in the conventional manner.

It is preferabie, though not essential, to provide an arrangement of contacts and pressure between contact members that will permit the short-circuit to be established between the stationary contacts 3l and 32 before contact 25 becomes disengaged therewith. This will insure continuity of service in the series-connected circuit without the presence of momentary flickering, arcing, or the possibility of a line surge occurring, which might accidently rupture other iilm cutouts. Another important reason for permitting engagement and disengage- The completed circuit will now beV nient of contacts in the above order, is that whenused 75 with systems incorporating gaseous discharge lamps, such asmercuryvaporlamps, thereY isY considerableY dangerY of destructive flashover when attempting to restart these lamps if current is even momentarily interrupted. On interruption of current, high pressures in the 'lamp will be sustained with consequent high internal electrical resistance which would require arelatively higher starting voltage resulting in the destructive flashover.

it will be seen that when themovable parts are rotated to the position shown in Fig. 2, that both the iilm cutout 3f? and2 the conducting, socket 24 will be entirely out of electrical' contact with any electrically alive parts, and maintenance' operations maybe conducted on them without danger of Contact by an operator with those parts.

cutout may be-replacedby simply springing the contact 2% away from the contact 25, removing the ruptured cutout, and replacing it with a new one. lf it is so desired, the pin 11 may be removed from the hook portions l of the trunnions 9, whereby the entire globe unit with the receptacle 2d will be free from the housing 3 for removal to street level for any repairs, cleaning, or replacements.

As has been previously stated, it is within the provinceof this invention to provide a receptacle (not shown) on a separate pivot structure frorn'the hinge 8 of the luminaire l without interfering with the operating characteristics of the invention.

it is also to be noted that the device may be installedin conventional vertically mounted lamps to provide-theY same functions and with very little modification ofthe parts illustrated and described.

It will be apparent that there has been provided a novel lamp holder assembly for a luminaire of either the enclosed or the open type, which assembly is especially applicable to a series-connected luminaire for maintaining continuity of service-in the remainder of the lampsfor, said globe assembly being movable from a closed position to an open position relative to said housing; a first pairv of contact members biased towards eectrical engagement with one another and arranged to complete an electrical series circuit on said engagement, a second electrical circuit including a conducting lamp socket and a second pair of contact members insulated from one another by means of a film cutout interposed therebetween and arranged for separable individual engagement with a respective contact of said first pair of contact members, one of said pairs being secured to said globe assembly for concurrent movement therewith for alternatively connecting said second circuit in series relationship with said rst mentioned series circuit and physically separating said rst pair of contact members on movement of said globe assembly towards closed position, and to concurrently release said lirst pair of contact members towards engaged position and electrically isolate said second circuit from said first mentioned series circuit on movement of said globe assembly to open position.

2. In a luminaire comprising a stationary housing and a globe assembly pivotally mounted thereon and providing a removable closure therefor, said globe assembly being pivotally rotatable from a closed position to an open position relative to said housing; a first pairV of contact members biased towards electrical engagement with one another and arranged to complete au. electrical series circuit on said engagement, a second electrical circuitincluding a conducting lamp socket and a second pair of'contaet members insulated from one another by means of a iilm cutout .interposed therebetween and arranged for separable individual engagement with a respective contact of said rst pair of Contact members, one of said pairs being secured to said globe assembly for concurrent rotative movement therewith for alternatively connecting said second circuit in series relationship with said rst mentioned series circuit and physically separating said rst pair of contact members on rotation of said globe assembly towards closed position, and to concurrently release said first pair of contact members towards engaged position and electrically isolate said second circuit from said first mentioned series circuit on rotation of said globe assembly to open position.

3. In a luminaire comprising a stationary housing and a globe assembly providing a removable closure therefor, said globe assembly being movable from a closed position to an open position relative to said housing; a pair of stationary contact members positioned in said housing arranged for series-circuit line connection and biased towards electrical engagement with one another to complete said connection, and a conducting lamp socket secured to said globe assembly for concurrent movement therewith and having a pair of spaced-apart contacts, each of said spaced-apart contacts in separable engagement with a respective one of said stationary contact members and concurrently urging said stationary contact members toward electrical disengagement with one another on movement of said globe assembly to closed position, whereby said series-circuit is completed through said lamp socket on movement of said globe assembly to closed position and whereby said spaced-apart contacts and said socket will be completely electrically isolated from said series-circuit connection on movement of said globe assembly to open position.

4. In a luminaire comprising a stationary housing and a globe assembly providing a removable closure therefor, said globe assembly being movable from a closed position to an open position relative to said housing; a pair of stationary contact members positioned in said housing arranged for series-circuit line connection and biased towards electrical engagement with one another to complete said connection, and a conducting lamp socket secured to said globe assembly for concurrent movement therewith and having a pair of spaced-apart contacts normally insulated from one another by means of a film cutout interposed therebetween, each of said spaced-apart contacts in separable engagement with a respective one of said stationary Contact members and concurrently urging said stationary contact members toward electrical disengagement with one another on movement of said globe assembly to closed position, whereby said seriescircuit is completed through said lamp socket on movement of said globe assembly to closed position and whereby said spaced-apart contacts and said socket will be completely electrically isolated from said series-circuit connection on movement of said globe assembly to open position.

5. In a luminaire comprising a stationary housing and a globe assembly pivotally mounted thereon and providing a removable closure therefor, said globe assembly being pivotally rotatable from a closed position to an open position relative to said housing; a pair of stationary contact members positioned in said housing arranged for series-circuit line connection and biased towards electrical engagement with one another to complete said connection, and a conducting lamp socket secured to said globe assembly for concurrent rotatable movement therewith and having a pair of spaced-apart contacts normally insulated from one another by means of a film cutout interposed therebetween, each of said spaced-apart contacts in separable engagement with a respective one of said stationary Contact members and concurrently urging said stationary contact members toward electrical disengagement with one another on rotation of said globe assembly to closed position, whereby said series-circuit is completed through said lamp socket on pivotal movement of said globe assembly to closed position and whereby said spaced-apart contacts and said socket will be completely electrically isolated from said series-circuit connection on rotation of said globe assembly to open position.

References Cited in the le of this patent UNITED STATES PATENTS 471,730 Dillon Mar. 29, 1892 668,887 Spies Feb. 26, 1901 1,366,914 King Feb. 1, 1921 1,976,657 Cole Oct. 9, 1934 2,289,160 Yost July 7, 1942 2,584,671 Cator et al. Feb. 5, 1952 FOREIGN PATENTS 183,320 Switzerland June 16, 1936 1,047,134 France July 15, 1953 

